A headlamp for a motor vehicle

Abstract: A lamp-within-a-lamp headlamp unit includes an inner lamp body (102) which is adjustably received within a first end of an outer lamp housing (104). A second end of the outer lamp housing defines a lens (104F) through which light is projected from the headlamp unit. The inner lamp body (102) sealably receives a lamp bulb (108) through a bulb access opening in a first end of the lamp body (102) which is accessed through the first end of the outer housing ((104). Light is projected from the second end (102b) of the lamp body (102) which can be open if appropriate focusing reflectors are provided adjacent the lamp bulb (108) or closed by an internal lens. An area surrounding the second end (102b) of the lamp body (102) is sealed to the outer lamp housing (104) by a flexible inner seal (102) which extends between the lamp body and an inner portion of the outer lamp housing. The flexible inner seal (106) permits the inner lamp body (102) to be adjusted relative to the outer lamp housing (104) which is secured to a motor vehicle for aligning or aiming the light beam projected from the headlamp unit. At the same time, the flexible inner seal (106) is sufficiently resilient so as to provide shock adsorbing support for the inner lamp body. The inner sealed headlamp permits alignment or aiming devices for the headlamp to be open to the atmosphere. A one-way vent (136) may be installed in the outer lens of the outer lamp housing (104) or a lens extension which extends between the outer lens (104F) and the first end of the outer lens housing.

Description: The present invention relates in general to headlamps for a motor vehicle and, more particularly, to an improved lamp-within-a-lamp headlamp design having an inner seal between an inner lamp body and an outer headlamp housing. Headlamps for motor vehicles have evolved from sealed beam systems wherein self-contained headlamp units each include one or two filaments, a reflector and a lens, all of which are formed into a glass shell with terminals extending out the back of the unit for electrical connections to the filament or filaments. Such sealed headlamp units are mounted into support frames which are adjusted typically from the front of the vehicle to properly align or aim the light beams projected from the vehicle. To simplify headlight installation in a vehicle, adjustment of headlamp alignment and replacement of burned-out headlamp filaments, headlamp units have been designed which are adjustably supported within a vehicle for receiving a headlamp bulb, typically a halogen bulb, from the rear of the unit. Such improved headlamp units eliminate substantial amounts of waste when headlamp filaments burn out and must be replaced. Headlamp alignment or aiming is simplified and typically performed from the rear of the headlamp unit. Exemplary headlamp units of this form are disclosed in U.S. Patents No. 4,471,413 and No. 4,569,007. Another form of improved headlamp unit is disclosed, for example, in U.S. Patent No. 4,574,334. This form of headlamp unit includes a lamp-within-a-lamp, i.e. a reflector which supports a bulb is adjustably supported within a lamp housing. The known headlamp comprises an access opening for inserting a headlamp bulb within the housing, and horizontal lamp body orientation adjustment means accessible from a rear end of the housing. As is apparent from this patent, the inner lamp or reflector is supported near the ends of adjustment screws, pivot members and the like such that it is subject to being deflected due to forces produced as the vehicle including the headlamp unit is driven. Further, the lamp housing is sealed such that dirt and moisture cannot accumulate on the lens which is on the front of the reflector. Since the lamp housing is sealed, all alignment adjusters must also be sealed where they enter the housing or else the housing seal will be compromised. The added complexity required by sealing the alignment adjusters is also apparent from a review of this patent. A headlamp unit as set forth in the preamble of claim 1 is disclosed in US-A 3 018 364. One headlamp unit described in this specification comprises a lamp body defining an inner cavity for receiving and supporting a headlamp bulb in a first end of said inner cavity and projecting light generated by said bulb from a second end of said inner cavity opposite to said first end; a housing having an interior for adjustably receiving said lamp body in a first end thereof and defining a lens in the second end thereof opposite to said first end such that light projected from said lamp body is projected through said lens; and flexible inner seal means extending between said second end of said lamp body and said housing for sealing to said inner cavity of said lamp body a portion of the interior of said housing extending from said lens approximately to said lamp body. In this unit adjustment of horizontal and vertical alignment is effected by moving the whole housing in an external mounting and the lamp body is mounted in a permanently sealed portion of the housing. Changing a bulb requires the lamp body to be removed through the front of the housing. The present invention provides, by the measures set forth in the characterising part of claim 1 in combination with those in the preamble, an improved design of sealed headlamp unit for a motor vehicle in which both alignment of the lamp body and replacement of the bulb can be effected more conveniently. Thus an embodiment of a lamp-within-a-lamp headlamp unit in accordance with the invention comprises an inner lamp body which is adjustably received within a first (rear) end of an outer lamp housing, to which it is attached by a flexible seal, and is supported there by means for adjusting its horizontal and vertical orientation which are similarly accessible from the open rear end of the housing. The second (front) end of the housing defines a lens through which light is projected from the headlamp unit. The inner lamp body sealably receives a lamp bulb through a bulb access opening in a first end of the lamp body which extends beyond or is accessed through the first end of the outer housing. Light is projected from the second end of the lamp body which can be open if appropriate focusing reflectors are provided adjacent the lamp bulb or closed by an internal lens. An area surrounding the second end of the lamp body is sealed to the outer lamp housing by a flexible inner seal which extends between the lamp body and an inner portion of the outer lamp housing. The flexible inner seal permits the inner lamp body to be adjusted relative to the outer lamp housing which is secured to a motor vehicle for aligning or aiming the light beam projected from the headlamp unit. At the same time, the flexible inner seal is sufficiently resilient so as to provide shock absorbing support for the inner lamp body. The inner sealed lamp-within-a-lamp design of the present invention maintains a forward portion of the outer lamp housing and the interior of the inner lamp body sealed against the entrance of dirt or moisture whether an inner lens is provided or not. If an inner lens is provided, the inner lamp body is sealed between the inner lens and the sealingly received lamp bulb, if not, the inner lamp body is in communication with the forward portion of the outer lamp housing and the entire volume is sealed between the sealingly received lamp bulb and the inner seal. A one-way vent may be installed in the outer lens of the outer lamp housing or a lens extension which extends between the outer lens and the first end of the outer lens housing. The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a vertical section through a headlamp according to the invention; Fig. 2 is a horizontal section through the headlamp of Fig. 1; and Fig. 3 is a partially broken-away perspective view of an inner seal used in the headlamp of Figs. 1 and 2. In Figs. 1 and 2, a lamp-within-a-lamp headlight unit 100 for a motor vehicle is shown. In the illustrated embodiment, the headlamp unit 100 includes lamp body means comprising an inner lamp body 102, housing means comprising an outer housing 104, and flexible inner seal means comprising a seal 106 as best shown in Fig. 3. The inner lamp body 102 sealingly receives a headlamp bulb 108 in a first end 102a of an inner cavity defined by the inner lamp body 102. When the bulb 108 is lighted, light is projected from a second end 102b of the inner lamp body 102. In the illustrated embodiment of Figs. 1 and 2, inner lens means comprising an inner lens 110 is secured to the second end 102b of the inner lamp body 102 such that light from the bulb 108 passes through the lens 110. As illustrated, the inner lens 110 is secured to one side of a flange 112 which surrounds and extends outwardly from the second end 102b of the inner lamp body 102. The inner lamp body 102 is adjustably received in the interior of the outer housing 104. As illustrated in Fig. 2, the inner lamp body 102 defines a support boss 114 which includes a generally spherical aperture for receiving a ball extension 116 mounted to the outer housing 104. This ball-joint mounting permits the inner lamp body to be pivoted about the ball 116a of the ball extension 116. The inner lamp body 102 also defines a horizontal adjustment member 118 to which a horizontal adjusting screw 120 is mounted. The horizontal adjusting screw 120 is threadedly received in a connector 122 secured to the outer housing 104 for horizontal adjustment of the inner lamp body 102 and hence the headlight unit 100. An opening 104O provides access for removal and insertion of the bulb 108. The inner lamp body 102 also defines a vertical adjustment member 124 which extends through an opening 104a of the outer housing 104. The vertical adjustment member 124 is engaged by a vertical adjusting device (not shown) which moves the member 124 up and down (in and out of the drawing as shown in Fig 2). The inner lamp body 102 is mounted in the interior of a first end or rear portion 104R of the outer housing 104. The second end or front portion of the outer housing 104 is a lens 104F through which light is projected from the inner lamp body 102 when the bulb 108 is lighted. In the illustrated embodiment, the lens 104F is connected to the rear portion 104R of the outer housing 104 by a lens extension member comprising an intermediate portion 104I of the outer housing 104. The seal 106 is continuous and includes an inner bead 126 which is sealingly received in a groove in the rear of the flange 112 which surrounds and extends outwardly from the second end 102b of the inner lamp body 102. The inner bead 126 of the seal 106 is mechanically and also preferably adhesively sealed to the rear of the flange 112 of the inner lamp body 102. The seal 106 defines a seal loop 106L which extends from the inner lamp body 102 to the outer housing 104. The seal 106 includes a dual beaded outer flange 128 which is mechanically sealed by being engaged between conformably formed flanges 130, 132 on the rear portion 104R and the intermediate portion 104I of the outer housing 104, respectively. The outer flange 128 may alternately or additionally be adhesively secured to the outer housing 104. The headlight unit 100 is secured to a motor vehicle, represented by fragmented pieces 134 in Figs. 1 and 2, in a conventional manner which will not be described herein. Vent means comprising a one way (outward) vent 136 preferably is provided through the lens or through the lens extension, intermediate portion 104I of the outer housing 104 as shown in Fig. 1, to ventilate the sealed portion of the interior of the outer housing 104. In some headlight units, the inner lens 110 may be eliminated by forming the interior portion of the inner lamp body 102 as a complex reflector which not only reflects light toward the outer lens 104F but also focuses the light. The illustrated structure of the flange 112 on the inner lamp body 102 is adapted for both type headlight units, i.e. with or without an inner lens 110. The rear portion of the flange 112 defines a groove for receiving the seal 106 while the front of the flange 112 defines a ridge to which a lens, such as the lens 110, can be secured or not depending upon the design of the headlight unit. The headlight unit will still function as proposed with or without the inner lens 110. If the lens 110 is provided, the front portion of the outer housing is sealed from the outer lens 104F approximately to the inner lens 110 to prevent moisture and dirt from entering the sealed portion and dimming the light projected from the headlight unit. If the lens is not provided, the front portion of the outer housing is sealed to the inner cavity of the lamp body 106 which is also sealed by proper insertion of the bulb 108 into the lamp body 106. As should be apparent from a review of the foregoing description and the drawing figures, the headlight unit 100 according to the present invention permits the adjusting mechanisms and bulb access into the outer housing 104 to be open to the atmosphere rather than being sealed as before. This arrangement permits much simpler construction and hence reduced cost for the headlight unit 100. In addition to providing a sealed interior for the headlight unit 100, the seal 106 is sufficiently resilient that it provides shock absorbing support for the inner lamp body 106. The seal loop 106L enhances flexibility of the seal 106 and permits movement of the seal 106 which facilitates adjustment of the inner lamp body 102 relative to the outer housing 104.

Claims: A headlamp unit for a motor vehicle comprising: a lamp body (102) defining an inner cavity for receiving and supporting a headlamp bulb (108) in a first end (102a) of said inner cavity and projecting light generated by said bulb from a second end (102b) of said inner cavity opposite to said first end (102a); a housing (104) having an interior for adjustably receiving said lamp body (102) in a first end (104R) thereof and defining a lens (104F) in the second end thereof opposite to said first end such that light projected from said lamp body (102) is projected through said lens (104F); and flexible inner seal means (106) extending between said second end (102b) of said lamp body (102) and said housing (104) for sealing to said inner cavity of said lamp body a portion of the interior of said housing (104) extending from said lens (104F) approximately to said lamp body (102), characterised in that said lamp body (102) has a bulb access opening in its first end (102a) for sealably receiving said bulb (108) therethrough; said first end (104R) of said housing (104) defines an access opening (104 O) for inserting said headlamp bulb (108) into and removing it from said lamp body; and said lamp body (102) is supported within said housing (104) by lamp body orientation adjustment means (114, 116 118, 120, 124), accessible from said first end (104R, 104a, 122) of said housing, for adjusting the horizontal and vertical orientation of said lamp body within said housing. A headlamp unit as claimed in claim 1, further comprising an inner lens (110) secured to said lamp body (102) such that light projected from said lamp body passes through said inner lens before being projected through the lens (104F) of the housing (104). A headlamp unit as claimed in claim 1 or claim 2, wherein said lens (104F) of the housing (104) includes means (136) for venting the sealed portion of the interior of the housing. A headlamp unit as claimed in claim 1 or claim 2, wherein the housing (104) further comprises a lens extension (104I) for interconnecting the lens (104F) of the housing (104) and the first end (104R) of the housing. A headlamp unit as claimed in claim 4 , wherein said lens 0extension (104I) of the housing (104) includes means (136) for venting the sealed portion of the interior of the housing. A headlamp unit as claimed in any preceding claim, wherein the flexible inner seal (106) continuously surrounds said second end (102b) of the lamp body (102) and is sufficiently resilient to provide shock absorbing support for the lamp body. A headlamp unit as claimed in any preceding claim, wherein the flexible inner seal (106) is mechanically secured to the lamp body (102) and to the housing (104). A headlamp unit as claimed in any of claims 1 to 6, wherein the flexible inner seal (106) is mechanically secured to the lamp body (102) and adhesively secured to the housing (104). A headlamp unit as claimed in any preceding claim, wherein the first portion (104R) of the housing (104) includes a back wall positioned substantially opposite to the lens (104F) of the housing and having an opening (104 O) therein sized for inserting and removing the headlamp bulb.

Inventors: VAN OEL ROBERT W, WINOWIECKI JAMES B, VAN OEL, ROBERT W., WINOWIECKI, JAMES B.
Applicants: FORD FRANCE, FORD MOTOR CO, FORD WERKE AG, FORD FRANCE S. A., FORD MOTOR COMPANY LIMITED, FORD-WERKE AKTIENGESELLSCHAFT
Application year: 1994
Main classification: B60Q1
IPC codes: G01M11, F21V13, F21V31, F21S8, F21V17, B60Q1, F21V5, F21V15